Radio transmitting and receiving system



Feb. 2, 1937.

I.VVOLFF RADIO TRANSMITTING AND RECEIVING SYSTEM Filed Nov. 30, 1934 2 Sheets-Sheet 1 METALLIC INvL'NfroH Ir ving Wo lff BY J vFeb. 2, 1937. woLFF V 2,069,513

RADIO TRANSMITTING AND RECEIVING SYSTEM Filed Nov. so, 1934 2 sheets-sheet 2 V fa" V BY?? Egg Q Q /117'0 NEY Patented Feb. 2, 1937 UNITEDY STATES PATENT OFFICE RADIO TRANSMITTING AND RECEIVING SYSTEM Delaware Application November 30, 1934, Serial No. 755,286 Y 8 Claims.

This invention relates to radio transmitting and receiving systems, and more particularly to a device of this character in combination with adjustable means for simultaneously varying the exposed dimensions of an antenna in order to maintain constant its directional radiation characteristic.

An object of my invention is to provide a construction of high frequency antenna apparatus having means for accurately adjusting different sections thereof for maintaining optimum radiating characteristics.

Another object of my invention is to combine in apparatus of the character above suggested an antenna length control with control of a tuning device.

Another object of my invention is to provide an antenna system having telescopically disposed radiating sections and telescopically disposed non-radiating sections, all of which may be simultaneously adjusted from a uni-control device. g

When an antenna system is used for long Wave radio transmission or reception at a series of diierent wave lengths, good results can be obtained by re-tuning the electrical circuits of the associated radio apparatus to give the desired response at each frequency. When working with short waves, however, the antenna may be of the same o-rder of magnitude as, or longer than, the length of the wave being radiated or received. vIt then becomes necessary to re-proportion the .exposed surfaces of the antenna with respect to the radiated wave, in addition to re-tuning the electrical circuits of the radio apparatus. Failure to provide suitable adjustment of the antenna system itself involves serious energy losses. Furthermore, the desired directional characteristic cannot be satisfactorily maintained for eiicient transmission and reception between two geographically spaced antennae unless some means are provided for variably exposing different portions of each antenna according to thev operating Wave length.

In carrying out my invention I prefer to' arrange the various movable elements of the antenna system in such manner that their effective radiating length may be adjusted to any desired wave length for securing high operating eiciency of the radio communication system of which the antenna forms a part.

The foregoing objects and advantages oi my invention will best be understood upon reference to the following detailed description when (Cl. Z-33) fully extended,

Fig. 3 illustrates diagrammatically the current distribution on my antenna system when properly adjusted to radiate or to receive radio Waves of a given Wave length,

Fig. 4 illustrates diagrammatically the corresponding current distribution on an antenna system improperly adjusted, and

Fig. 5 shows diagrammatically how the directional response or radiating characteristic of a vertically disposed antenna system varies with diiferent Wave lengths.

My antenna system may be used either for radio transmission or reception. In either case, the antenna length should be some definite multiple of half the Wave length. It is desirable, therefore, to provide variable means for adjusting the apparatus so as to provide efficient transmission or reception at different frequencies. For making such adjustments it is again desirable that a uni-control device be provided in which both the antenna length and whatever tuning adjustment there may be incorporated in the radio apparatus shall be simultaneously adjusted to a desired frequency response. In the transmission and reception of ultrashort waves, it is of the utmost importance that Ythe minutest details of the radiating characteristics of an antenna system should be considered and adjusted to optimum operating conditions. Thus, if it is desired that the antenna arms be made to include three half-wave radiating sections, then these radiating sections should, by preference, be interconnected by nonradiating half-wave sections in order that a satisfactory Wave front may be obtained in the radiating characteristic. x

To illustrate this point I have shown in Fig. 3 an antenna system which is composed of three radiating sections 5, 6 and Y1, respectively, and two non-radiating sections 8 and 9. If each of these sections is adjusted to a Wave lengththen it will be seen that the current distribution is as indicated by the half-wave loops a., b' and c. The loop b has the-samephase as thetwo loops w is indicated as and c because the non-radiating half-wave sections 8 and 9 are interposed. If, on the other hand, a diierent frequency were to be impressed upon the antenna system and one to which it is not properly adjusted, the results obtained might be as shown in Fig, 4 where the antenna length The ineiiiciency of the system under these conditions becomes apparent when it is considered that the current distribution becomes broken up with phase reversals, as shown by the curves a', b' and c. In this case the radiating sections 5 6' and 1 are not of suitable length to impress half-wave length radiations symmetrically thereupon. Each section is, in fact, too short to comprehend a full half -wave. Furthermore, the non-radiating sections 8 and 9 are not of suitable length for transposing the phase in the desired manner, as shown in Fig. 3. 'I'he maximum radiating effect, instead of being perpendicular to the antenna axis, becomes tilted at an undesirable angle. InV

the example given the angle :62", approximately.` V

It is, therefore, for the purpose of avoiding such adverse conditions that I provide suitable adjustments inY my antenna system so that both the radiating sections and the non-radiating sections maybe varied in electrical length simultaneously. Referring now to Fig. 1, I show an antenna system suitable for radiating or receiving radio Waves. A pair of stationary tubular members II is provided. These are mounted upon insulating supports I3. The insulators I3 are preferably carried on a centrally disposed framework I2 which serves also to support the various moving elements comprised in the uni-control device, as well as a tuning condenser I4. The latter is shown merely for the purpose of illustrating how my uni-control device may be operated to simultaneously adjust both the antenna length and the resonant conditions of a radio network. The stationary sections I I are arranged to cooperate ,with telescoping sections I5. 'I'he'sections II and I may be considerably elongated or telescoped one within another so that the effective electrical length shall beon each side of the center of symmetry of the antenna system. Thus, if energy is applied to these sections through the leads I6, a half-wave length will be radiated from between the outer extremities of the two sections I5.

In order to obtain the necessary adjustment, each of the telescoping members I5 is provided internally with a nut I1 threaded to mesh each with a screw-threaded shaft I8, the turning of which may be eiiected by means of a crank I9 mounted on a shaft 20, which shaft carries a bevel pinion 2| meshing with a. bevel gear 22, the latter being mounted on an insulating member 23 into which the ends of the threaded shaft I8 are keysocketed.

The structural elements thus far described may be seen to be made suitably adjustable for producing a half-wave length of radiation on' the fixed sections II in cooperation with the adjustable sections I5. Further radiating sections Veach having an eifective radiating length of Y 2 are provided by the telescoping members 24 and by means of a driven 25. Each of the members 24 is secured to one or the other of the members I5, respectively. The mechanical juncture is in the form of an insulating member 26. A pair of insulators 36 have each a clearance hole therein for permitting the members 24 to slide up and down therein without Y danger of misalignment. Theinsulators 36 are mounted on any suitable support, as shown.

The telescoping members 25 are held in position telescoped within the members 24 and adjustably elongated by means of nuts 21 which mesh with the threaded shafts I8. Studs 31 are inserted through slots 38 and secured each to one of the telescoping members 25 to prevent the same from turning on its axis. The pitch of the thread along the portion-of the shaft I8 over which the nut 21 is movable is made approximately three times as great as the pitch of the thread over which the nut I1 is movable. Thus, the telescoping members 25 will be caused to be extended outwardly from and with respect to the members 24 approximately twice as fast as the outward extension of the member I5 with respect to the stationary members I I. The elongation of the sections 25 and 24taken together, is made twice as great as the elongation of the sections I5 and II, taken together, because in the first instance a half-wave length is required and in the second instance only a quarter-wave length is required. For the purpose of reversing the phase relation between the outer extremity of the member I5 with respect to the inner extremity of the member 24 I provide a loop having approximately an electrical wave length of- This loop consists of two straight tubular sec.- tions 28 and 29, each being adjustably telescoped Within the straight portions of a U-shaped tubular member 39. The section 28 is mountedoif the outer end of nie radiatingsecuon l5, the

connection thereto being made by means of a conductive member 3|. Likewise, the section 29` is connected to the radiating section 24 by means `of a conductive member 32. The electrical length of the circuit including the members 3|, 28, 30, 29 and 32 may be simultaneously adjusted to while any desired adjustment is correspondingly made with respect to the radiating sections. This U-shaped link is to be considered as nonradiating because, although each portion thereof is in itself a radiator, its overall effect is sub,-n

Y loop in its entirety may be adjustably shortened by controlling the position of the U-shaped member 3D along with the adjustment of the length of the radiating sections. This is preferably accomplished by means of a threaded rod 33 of in' sulating material which engages withv threaded portions of the U-shaped member 30. The turning of the threaded rod 33 may be accomplished pinion 35 which is either mounted on or made integral with the insulating member 23. The

4 pitch of the thread on the shaft 33, as Well as the gear ratio between the members 34 and 35. is suitably determined for obtaining an effective` electrical length equal to a half-Wave length on gear 34 meshing with a the 'non-radiating sct'io'nfor any vdesired adjustment of the effective Velectrical length Vof the radiating sections.

In order-to carry out the scheme as represented in Fig. 3, both radiating and non-radiating sections, as shown above the center'of Fig. 1 are duplicatedfbelow the center-line. A symmetry of parts may thus be obt-ained for any desired adjustment. Also, for any desired adjustment the centrally disposed quarter-wave length sections may be caused to cooperate to produce in eifect a single radiating section having a value ofwhereas each of the outer telescoping sections above and below the mid-sections may be adjusted to a value of and each of the non-radiating sections is also simultaneously adjustable to a value of- In Fig. 1 the telescoping sections have been shown in a fragmentary manner in order to give a better idea of the working parts, whereas in Fig. 2 the relationship between diameters and length of the various sections is, perhaps, a trifle better proportioned to exemplify the considerable length of the antenna system compared with its diameter. Also, in Fig. 2, the telescoping sections have been shown fully elongated. In other respects there is no difference in the showing of the two figures.

Fig. 5 shows diagrammatically how the directional characteristic of an antenna system such as mine varies with different operating wave lengths. The curve A has been plotted against different angles representing the axis of radiation with respect to the axis of the antenna system. The peak of energy radiation intensity is indicated as having a value of unity in a horizontal direction when the antenna axis is vertical. For such an antenna the directional pattern loses eciency very rapidly and has substantially a zero value at an angle 6 of approximately 70. Between the values 0:70 and 0=48 a phase reversal of energy takes place. Thence the curve of intensity rises slightly and then descends again to a zero value for projection of radio waves in a vertical direction, or where 0 equals 0.

Without changing the antenna length, but upon impressing thereon a wave having a value 1.25 the directional characteristic becomes altered according to the broken line indicated in the diagram. The peak intensity occurs in a direction where 0:62". Since the efficiency of wave propagation in a horizontal direction is the object generally sought, and since the efficiency in the case last illustrated by the broken line 1.25% is almost nil in a horizontal direction, it may readily be seen why it is so essential to adjust the antenna length so that each section shall have a value of approximately- In place of an antenna system having only three sections of a half-wave length each, it may be desired to employ any of the well known types of directional antenna and to provide therefor means for maintaining constant its directional characteristic at different frequencies. 'Although lI have disclosed herein. certain spelcie means for accomplishing the objects of my invention, these are given merely by way of eX- ample and are not to be construed as limitations to the scope of my invention. Other modifications willl suggest themselves to those skilled in the art. My invention, therefore, is to be considered as having as broad a scope as is permitted bythe prior art and by the spirit of the appended claims.

I claim as my inventio-n:

1. A radio system comprising an antenna, a resonant circuit, means for adjusting the dimensions of said antenna so that its effective length is substantially equal to an odd multiple greater than one of half wave lengths ofthe energy to be impressed thereon, means for reversing the phase between adjacent oppositely phased half wave antenna sections, means for adjustably tuning said resonant circuit, and a uni-control device operably connected to said antenna adjusting means, to said phase reversing means and to said tuning means for maintaining suitable coordination of the respective adjustments thereof.

2. A system in accordance with claim 1 characterized in that said antenna is' directional and means are provided in operable connection with said uni-control device for so adjusting the dimensions of the antenna as to maintain the directional pattern thereof substantially constant at different frequencies.

3. In a system combining an antenna device with radio apparatus, means for adjusting the effective antenna dimensions to a half-wave length of the radio energy and for adjusting the same to a multiple of said, half wave length, means for reversing the phase between adjacent oppositely phased half wave antenna lengths, means for tuning said apparatus in accordance with the wave length of the energy impressed on said antenna, and a uni-control device operatively connected to the first and second mentioned meansI for simultaneously varying the same in a mutually coordinated manner.

4. The combination as set forth in claim 3 characterized in that said antenna device is directional and means are provided in operable connection with said uni-control device for so adjusting the dimensions of the antenna as to maintain the directional pattern thereof substantially constant at diierent frequencies.

5. In a device of the class described, an antenna, .a radio-frequency tuning device, means for adjusting the dimensions of said antenna in proportion to one half of an odd multiple greater than one of the Wave length of a predetermined radio signal impressed upon said antenna, a phase-shifting section of antenna serially included between adjacent oppositely phased half wave antenna lengths, means for adjusting said tuning device to said wave length, means for maintaining the directional pattern of said antenna substantially constant at different frequencies, and a uni-control device operatively connected to the first mentioned means and to the said phase-shifting section for adjusting the same simultaneously.

6. A device in accordance with claim characterized in that said antenna is directional and means are provided in operable connection with said uni-control device for maintaining the directional pattern of said antenna substantially constant at different frequencies. 4.

said sections, means for so adjusting the exposed dimensions of the rst of said sections and the second mentioned sections as to maintain a uniform directional radiation characteristic at different Wave lengths, and uni-control means for 10 effecting said adjustments simultaneously.

8. In an antenna system, a plurality of telescopicaliy disposed tubular radiating sections of which an. outer Section and the exposed portion of an inner section constitute a half-wave-length radiator, a plurality of phase reversing sections interconnecting different sets of half -rwave-length radiators, and means for simultaneously adjusting the effective lengths both of radiators and of the phase reversing sections to obtain an optimum directional characteristic for a given wave length of energy impressed upon said system. IRVING WOIJF. 

